Drinking coffee isn't just about enjoyment anymore—it might also be a way to get some important health benefits. The body of evidence on coffee’s positive health effects is growing, and a 2015 study found that coffee was also associated with lower levels of coronary artery calcium, which could reduce the risk of having a heart attack. Published in the journal Heart, the study tracked 25,138 men and women without cardiovascular disease. When participants underwent a health screening that included a CT scan to determine coronary artery calcium levels, researchers discovered that:
Participants who drank 3 to 5 cups of coffee per day had the least amount of coronary artery calcium buildup.
The association between coffee intake and lower coronary artery calcium buildup remained even after adjusting for education, physical activity levels, family history of heart disease, and diet.
However, there are some important things to note in relation to this study. The study was observational and so can't prove a cause-and-effect relationship. It also didn’t distinguish between caffeinated and decaffeinated coffee; it's not clear, therefore, whether decaf would have had the same effects. Further, to get potential heart health benefits, a cup of coffee should contain 8 ounces, not 20 ounces (which is the amount some people might drink in a single cup). Despite these caveats, the 2015 study is consistent with other research showing that coffee may offer some protection against heart disease, type 2 diabetes, and Parkinson’s disease.